Siremata, Passanha & Brescovit, 2018

Passanha, Victor & Brescovit, Antonio D., 2018, On the Neotropical spider Subfamily Masteriinae (Araneae, Dipluridae), Zootaxa 4463 (1), pp. 1-73 : 62

Siremata new genus

Type species. Siremata valteri n. sp.

Etymology. The generic name is an anagram of Masteria and herein considered a feminine noun.

Diagnosis. Siremata differs from the other Masteriinae in the presence of microspines around the eyes ( Fig. 40B ), the quadrate pattern of the eyes, with the posterior median eyes being on a tubercle ( Fig. 40A ) and males with ventral megaspine in the median region of tibia I ( Fig. 40C ).

Description. Small-sized mygalomorph spiders, total length between 2.16̄4.25. Color: carapace in dorsal view, chelicerae and legs varying from whitish to dark brown, with variations of yellow, orange and light brown. Endites, labium and sternum light brown to whitish. Abdomen light brown or whitish. Clypeus narrow (0.01̄0.03) in relation to ALE. Chelicerae without rastellum. Basal segment of chelicerae with row of 9̄13 prolateral teeth and row of 10¯18 mesobasal denticles ( Fig. 41C ). Ocular tubercle wider than long, with six eyes; AME absent, posterior row straight, PME on elevated tubercle ( Fig. 40A ). Tegument around eyes with microspines ( Fig. 40B ). Labium wider than long, without cuspules. Endites without cuspules, with linear serrula on apical border ( Fig. 41A ). Sternum oval, longer than wide, without evident sigilla. Tarsus of all legs without scopulae, with few sensorial setae interspaced or many sensorial setae. Two superior tarsal claws, a row of teeth (5̄11), inferior claw with 2–4 teeth. Tibia I of males with ventral megaspine on medial portion ( Fig. 40C ), absent in Siremata lucasae n. sp. Cymbium of male palp with 2–4 apical spines. Trichobothria filiform, corrugated bases, with longitudinal keels ( Fig. 41B ); Legs with one dorsal trichobothrial row on tarsus and two, dorsal and dorso-retrolateral, on metatarsus and two dorsal on tibia. Tarsal organ without elevation with low and concentric keels ( Fig. 41D ). Palp with one row of trichobothria on tarsus and two on tibia. Abdomen with oval pulmonary opening. Posterior median spinnerets short with spigots on apex, australotheline crescent present. Posterior lateral spinnerets 3-segmented, elongated, apical segment with triangular apex, major ampulate spigots, aciniform spigots and pumpkiniforms spigots present on ventral face. Female palp with one or two ventral spines on tarsus base, tarsal claw with central row of 13̄14 teeth. Male palp: cymbium as wide as long, with short prolateral lobe, tibia with median retrolateral grouped spines or setae ( Fig. 42D , 44E ), absent in S. juruti n. sp. Palpal bulb elongated ( Fig. 42B , 44C ) or dorso-ventrally flattened ( Fig. 43B ̄C). Embolus elongate. Female genitalia: spermathecae bilobed, elongate ( Fig. 42F , Fig. 44E ) or short ( Fig. 43E ̄F). Glandular region short with large glands in ducts ( Fig. 42F , 44F ), except in S. juruti n. sp., not evident ( Fig. 43E–F ).

Species included. Siremata valteri n. sp., S. lucasae n. sp., S. juruti n. sp.

Distribution. Brazilian Amazon region ( Fig. 45).

Figures

FIGURE 40. Siremata new genus. A Siremata valteri n. sp., male (IBSP 167208), eyes, dorsal view; B S. juruti n. sp., male, (IBSP 167212), Microspines on eye region, dorsal view; C S. valteri n. sp., male (IBSP 167208), ventral medial megaspine on tibia I (right leg, proventral view); D S. juruti n. sp., male (IBSP 167212), australotheline crescent, ventral view. Abbreviations: PMS, Posterior median spinneret; MR, Membranous region; A, abdomen. Scale bar: A 100µm; B 10µm; C 200µm; D 100µm.

FIGURE 41. Siremata new genus. A Siremata valteri n. sp., male (IBSP 167208), serrula, lateral view; B Siremata lucasae n. sp., male (IBSP 167215), trichobothria of leg I, dorsal view; C Siremata valteri n. sp., male (IBSP 167208), teeth row of chelicerae, ventral view; D Siremata lucasae n. sp., male (IBSP 167215), tarsal organ of leg I, dorsal view. Scale bar: A 40µm; B 40µm; C 100µm; D 5µm.

FIGURE 42. Siremata valteri n. sp. (male and female, IBSP 167208). A Male eyes, dorsal view; B Palpal bulb, ventral view; C Embolus tip, ventral view; D Retrolateral grouped spines on palpal tibia, retrolateral view; E Ventral medial megaspine on tibia I (right leg, proventral view); F Female genitalia, dorsal view. Scale bar: A, B 100µm; C 10µm; D 100µm; E 200µm; F 50µm.

FIGURE 43. Siremata juruti n. sp. (male and female, IBSP 167212 and MPEG 8596). A Male eyes, dorsal view; B Embolus, ventral view; C Palpal bulb, ventral view; D Ventral medial megaspine on tibia I (right leg, proventral view); E, F Female genitalia, dorsal view. Scale bar: A 50µm; B 30µm; C, D, E, F 100µm.

FIGURE 44. Siremata lucasae n. sp. (male and female, IBSP 167215). A Male eyes, dorsal view; B Female genitalia, dorsal view; C Palpal bulb, retrolateral view; D Female genitalia, dorsal view; E Retrolateral grouped spines on palpal tibia, retrolateral view. Abbreviations: BG, basal groove. Scale bar: A 200µm; B, C 100µm; D 200µm; E 100µm.